Recently I have read the Sovrin white papers and in order to understand the ecosystem a bit better for myself, I made the overview in the picture attached. I have however noticed that the white papers were not very recent so in the meantime a lot of the framework could have changed due to the rapid development. So my questions are:

Is this picture still accurate or have there been significant changes?

What is in the current situation exactly registered on the identity ledger? The DIDs and the corresponding DID documents as listed in the bottom right corner?

What is the exact difference between Clients and Agents? Are agents build on top of clients? If so, what is it that an (edge) agent adds? A GUI? Wallet (software)? The private keys of the DID subject?

Rick, thanks for doing this. I think your overview picture is close, but as you said, there is some outdated Sovrin documentation out there (in particular the document called The Technical Foundations of Sovrin in the Sovrin library that has not been updated since Sept 2016). That makes it hard to build a completely current picture without some help. To answer your questions:

RickS:

Is this picture still accurate or have there been significant changes?

I think overall it is accurate. We don’t tend to use the term “Sovrin clients” as much as in the first Sovrin technical papers because the primary emphasis now is on agents (cloud and edge). But technically there is still client code that talks to the Sovrin ledger.

Also, as explained in the Sovrin Glossary, a Sovrin Identity does not necessarily consist of just one DID. It consists of the set of digital credentials that are shared by the Identity Owner with another party via a Connection. I’m not exactly sure how you’d capture that concept in an overview drawing of this type.

RickS:

What is in the current situation exactly registered on the identity ledger? The DIDs and the corresponding DID documents as listed in the bottom right corner?

Yes and no. Yes, public DIDs and DID documents are registered on the Sovrin ledger. But so are a handful of other specific data artifacts. @AndyTobin has written a document about “What Goes on the Ledger” but I don’t know if he has published it. Andy?

RickS:

What is the exact difference between Clients and Agents? Are agents build on top of clients? If so, what is it that an (edge) agent adds? A GUI? Wallet (software)? The private keys of the DID subject?

As I mentioned above, we now use the term “client” just to talk about code modules that talk directly to the Sovrin ledger. Otherwise we only talk about cloud agents and edge agents as discussed in the Sovrin white paper.

Besides the Sovrin client code, and agent maintains an associated digital wallet containing the private keys of the Identity Owner, a vault containing the owner’s digital credentials, and any associated processing logic and operational preferences of the Identity Owner. Both cloud agents and edge agents “speak” the Sovrin protocol for agent-to-agent communications, but only edge agents have an associated UI. Cloud agents are akin to email servers—they are “headless” and serve back-end functions like A2A message routing, push notifications to edge agents, and cloud-based backup and storage.